NTT Docomo agreed to give China-based electronics manufacturer Lenovo a licence covering standard essential patents including 5G.
In a brief statement, the operator noted it had licensed its standard essential mobile patents to more than 80 companies, including those in pools and through bilateral agreements.
Docomo stated it filed applications for 6G alongside adding to those submitted for 5G in its fiscal 2021, which ended on 31 March.
The company filed 1,079 Japanese patent applications in fiscal 2021, with 78 per cent covering 5G technologies.
It held some 4,000 patents in Japan and about 9,000 overseas as of end-March.
In 2018, the operator granted a licence covering its standards essential wireless patents to device maker Xiaomi.